US7470614B1 - Methods for fabricating semiconductor devices and contacts to semiconductor devices - Google Patents
Methods for fabricating semiconductor devices and contacts to semiconductor devices Download PDFInfo
- Publication number
- US7470614B1 US7470614B1 US11/355,474 US35547406A US7470614B1 US 7470614 B1 US7470614 B1 US 7470614B1 US 35547406 A US35547406 A US 35547406A US 7470614 B1 US7470614 B1 US 7470614B1
- Authority
- US
- United States
- Prior art keywords
- dielectric layer
- fill material
- depositing
- layer
- etching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76897—Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B41/00—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates
- H10B41/30—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates characterised by the memory core region
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S438/00—Semiconductor device manufacturing: process
- Y10S438/942—Masking
Definitions
- the present invention generally relates to semiconductor devices, and more particularly relates to methods for fabricating conductive contacts to semiconductor devices.
- FIG. 1 is a cross-sectional view of a conventional flash EEPROM memory cell.
- the cell 10 is formed on a substrate 12 , having a heavily doped drain region 14 and source region 16 embedded therein.
- the drain and source regions typically contain lightly doped deeply diffused regions 18 , 20 , respectively, and more heavily doped shallow diffused regions 22 , 24 , respectively, embedded into the substrate 12 .
- a channel region 26 separates the drain region 14 and source region 16 .
- the cell 10 typically is characterized by a vertical gate stack 36 of a tunnel oxide layer 28 , a floating gate 30 over the tunnel oxide, an interlevel dielectric layer 32 , and a control gate 34 over the interlevel dielectric layer.
- a conductive contact 50 is made to the control gate 34 , source region 16 , and/or the drain region 14 to access the memory device and allow interconnections between the memory device and other devices of the IC, as illustrated in FIG. 2 .
- a conductive contact 50 is an opening through one or more insulating layers 40 that is subsequently filled with a conductive material to form a contact to a device region.
- the conductive material forming the contact which often takes the form of a plug, may be tungsten or other metals.
- fabrication of the contacts to a memory device within the tolerances allowed by the relevant design rules becomes more difficult and has resulted in complex integration schemes for patterning, etching and filling to form the contacts. Misaligned contacts, such as contact 52 , pose a significant challenge and can severely reduce device yield.
- a method for fabricating a semiconductor device comprises the steps of providing a semiconductor substrate and forming two members extending from the semiconductor substrate and separated by a portion of the semiconductor substrate.
- a first semiconductor device and a second semiconductor device are formed in and on the semiconductor substrate and each comprise a common impurity doped region that is disposed within the portion of the semiconductor substrate.
- a dielectric layer is deposited overlying the two members, the semiconductor devices, and the common impurity doped region to a thickness such that a depression overlying the impurity doped region is formed.
- a fill material is deposited overlying the dielectric layer to substantially fill the depression and a portion of the dielectric layer is etched.
- a masking layer is deposited overlying the dielectric layer and the fill material and a portion of the masking layer is removed to expose the fill material.
- the fill material and the dielectric layer are etched to form a via through the dielectric layer and a conductive material is deposited within the via such that the conductive material is electrically coupled to the impurity doped region.
- a method for fabricating a semiconductor structure comprises the steps of providing a substrate and forming two parallel members that extend from the substrate and that are separated by a first distance. Two semiconductor devices are formed on the substrate and are separated by a second distance. An impurity doped region is formed within the substrate and is electrically coupled to the two semiconductor devices. A dielectric layer is deposited overlying the two parallel members, the two semiconductor devices, and the impurity doped region and a fill material is deposited overlying the dielectric layer. The fill material has an etch rate that is different from the etch rate of the dielectric layer when subjected to an etch chemistry. The fill material is polished to expose a surface of the dielectric layer and the surface of the dielectric layer is etched.
- a masking layer is deposited overlying the dielectric layer and the fill material and a portion of the masking layer that overlies the fill material is removed to expose the fill material.
- the fill material and the dielectric layer overlying the impurity doped region are etched.
- a conductive material is deposited overlying the impurity doped region and in electrical contact with the impurity doped region.
- a method for contacting a semiconductor device also is provided.
- the method comprises the steps of providing a substrate and forming two spacers disposed a first distance from each other and extending a second distance from the substrate.
- Two semiconductor devices are formed in and on the substrate and are disposed a third distance from each other.
- the two spacers and the two semiconductor devices form an area of the substrate that is substantially bounded by the two semiconductor devices and the two spacers.
- the area comprises an impurity doped region common to both semiconductor devices.
- a dielectric layer is conformally deposited overlying the two semiconductor devices, the two spacers, and the impurity doped region such that a depression in the dielectric layer is formed overlying the impurity doped region.
- the dimensions of the depression depend on the first distance, the second distance and the third distance.
- a fill material is deposited within the depression.
- a portion of the dielectric layer is etched with an etch chemistry that is selective to the fill material.
- a masking layer is deposited overlying the dielectric layer and the fill material and is polished to expose the fill material.
- the dielectric layer and the fill material are etched to form a via using the masking layer as a mask.
- a conductive contact is formed within the via.
- FIG. 1 is a cross-sectional view of a conventional flash EEPROM memory device with a floating gate
- FIG. 2 is a cross-sectional view of conductive contacts electrically coupled to conventional flash EEPROM memory devices
- FIGS. 3-38 illustrate, in cross section, method steps for fabricating a conductive contact to a semiconductor device in accordance with exemplary embodiments of the present invention.
- FIGS. 3-38 illustrate, in cross section, method steps for fabricating a conductive contact to a semiconductor device in accordance with exemplary embodiments of the present invention.
- FIGS. 3-38 illustrate, in cross section, method steps for fabricating a conductive contact to a semiconductor device in accordance with exemplary embodiments of the present invention.
- FIG. 3 is a top view of a semiconductor structure with spacers formed upon a substrate in accordance with various steps of an exemplary embodiment of the method of the present invention.
- FIG. 3 illustrates cross-sectional axes 4 - 4 and 5 - 5 ;
- FIG. 4 is a cross-sectional view of the semiconductor structure of FIG. 3 taken along cross-sectional axis 4 - 4 ;
- FIG. 5 is a cross-sectional view of the semiconductor structure of FIG. 3 taken along cross-sectional axis 5 - 5 ;
- FIG. 6 is a top view of the semiconductor structure of FIG. 3 formed in accordance with additional steps of an exemplary embodiment of the method of the present invention
- FIG. 7 is a cross-sectional view of the semiconductor structure of FIG. 6 taken along cross-sectional axis 7 - 7 ;
- FIG. 8 is a cross-sectional view of the semiconductor structure of FIG. 6 taken along cross-sectional axis 8 - 8 ;
- FIG. 9 is a top view of the semiconductor structure of FIG. 6 formed in accordance with additional steps of an exemplary embodiment of the method of the present invention.
- FIG. 10 is a cross-sectional view of the semiconductor structure of FIG. 9 , taken along the cross-sectional axis 10 - 10 ;
- FIG. 11 is a cross-sectional view of the semiconductor structure of FIG. 9 , taken along the cross-sectional axis 11 - 11 ;
- FIG. 12 is a cross-sectional view of the semiconductor structure of FIG. 9 , taken along the cross-sectional axis 12 - 12 ;
- FIG. 13 is a top view of the semiconductor structure of FIG. 9 formed in accordance with additional steps of an exemplary embodiment of the method of the present invention.
- FIG. 14 is a cross-sectional view of the semiconductor structure of FIG. 13 , taken along the cross-sectional axis 14 - 14 ;
- FIG. 15 is a cross-sectional view of the semiconductor structure of FIG. 13 , taken along the cross-sectional axis 15 - 15 ;
- FIG. 16 is a cross-sectional view of the semiconductor structure of FIG. 13 , taken along the cross-sectional axis 16 - 16 ;
- FIG. 17 is a cross-sectional view of the semiconductor structure of FIG. 14 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 18 is a cross-sectional view of the semiconductor structure of FIG. 15 , taken along the same cross-sectional axis as FIG. 15 , formed in accordance with the steps of FIG. 17 ;
- FIG. 19 is a cross-sectional view of the semiconductor structure of FIG. 16 , taken along the same cross-sectional axis as FIG. 16 , formed in accordance with the steps of FIG. 17 ;
- FIG. 20 is a cross-sectional view of the semiconductor structure of FIG. 17 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 21 is a cross-sectional view of the semiconductor structure of FIG. 19 , taken along the same cross-sectional axis as FIG. 19 , formed in accordance with the steps of FIG. 20 ;
- FIG. 22 is a cross-sectional view of the semiconductor structure of FIG. 20 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 23 is a cross-sectional view of the semiconductor structure of FIG. 18 , taken along the same cross-sectional axis as FIG. 18 , formed in accordance with the steps of FIG. 22 ;
- FIG. 24 is a cross-sectional view of the semiconductor structure of FIG. 21 , taken along the same cross-sectional axis as FIG. 21 , formed in accordance with the steps of FIG. 22 ;
- FIG. 25 is a cross-sectional view of the semiconductor structure of FIG. 22 , taken along the same cross-sectional axis as FIG. 22 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention
- FIG. 26 is a cross-sectional view of the semiconductor structure of FIG. 24 , formed in accordance with further steps of FIG. 25 ;
- FIG. 27 is a cross-sectional view of the semiconductor structure of FIG. 25 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 28 is a cross-sectional view of the semiconductor structure of FIG. 23 , taken along the same cross-sectional axis as FIG. 23 , formed in accordance with the steps of FIG. 27 ;
- FIG. 29 is a cross-sectional view of the semiconductor structure of FIG. 26 , taken along the same cross-sectional axis as FIG. 26 , formed in accordance with the steps of FIG. 27 ;
- FIG. 30 is a cross-sectional view of the semiconductor structure of FIG. 27 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 31 is a cross-sectional view of the semiconductor structure of FIG. 28 , taken along the same cross-sectional axis as FIG. 28 , formed in accordance with the steps of FIG. 30 ;
- FIG. 32 is a cross-sectional view of the semiconductor structure of FIG. 29 , taken along the same cross-sectional axis as FIG. 29 , formed in accordance with the steps of FIG. 30 ;
- FIG. 33 is a cross-sectional view of the semiconductor structure of FIG. 20 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 34 is a cross-sectional view of the semiconductor structure of FIG. 21 , taken along the same cross-sectional axis as FIG. 21 , formed in accordance with the steps of FIG. 33 ;
- FIG. 35 is a cross-sectional view of the semiconductor structure of FIG. 33 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 36 is a cross-sectional view of the semiconductor structure of FIG. 34 , taken along the same cross-sectional axis as FIG. 34 , formed in accordance with the steps of FIG. 35 ;
- FIG. 37 is a cross-sectional view of the semiconductor structure of FIG. 20 , formed in accordance with further steps of an exemplary embodiment of the method of the present invention.
- FIG. 38 is a cross-sectional view of the semiconductor structure of FIG. 21 , taken along the same cross-sectional axis as FIG. 21 , formed in accordance with the steps of FIG. 37 .
- FIGS. 3-38 illustrate method steps for manufacturing a semiconductor structure 100 that provides contact to a semiconductor device, such as flash EEPROM memory cell 10 , or any other suitable semiconductor device such as a transistor, a logic device, or the like.
- FIGS. 3-38 illustrate various top views and cross-sectional views of semiconductor structure 100 .
- Various steps in the manufacture of semiconductor structure 100 including the semiconductor devices thereof, are well known and so, in the interest of brevity, many conventional steps will only be mentioned briefly herein or will be omitted entirely without providing well known process details.
- silicon substrate 102 As illustrated in FIGS. 3-5 , the manufacture of semiconductor structure 100 begins by providing a silicon substrate 102 .
- silicon substrate will be used to encompass the relatively pure silicon materials typically used in the semiconductor industry as well as silicon admixed with other elements such as germanium, carbon, and the like.
- the term “silicon substrate” also is used to encompass the substrate itself together with metal or insulator layers that may overly the substrate.
- Silicon substrate 102 may be a bulk silicon wafer or a thin layer of silicon on an insulating layer (commonly known as a silicon-on insulator wafer or SOI wafer) that, in turn, is supported by a silicon carrier wafer.
- a silicon nitride layer 104 is deposited on the silicon substrate 102 .
- the silicon nitride layer 104 can be deposited, for example, by low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD) from the reaction of trichlorosilane or dichlorosilane and ammonia.
- LPCVD low pressure chemical vapor deposition
- PECVD plasma enhanced chemical vapor deposition
- a conductive contact can be formed to electrically couple a semiconductor device to an overlying conductive line while a sufficient amount of insulating material overlies the semiconductor device to insulate the semiconductor device from unrelated conductive lines.
- the silicon nitride layer 104 has a thickness in the range of about 200 nm to about 400 nm.
- a layer of photoresist (not shown) is applied to the surface of silicon nitride layer 104 and is photolithographically patterned to serve as an etch mask. Silicon nitride layer 104 then is etched to form a plurality of trenches 106 that are spaced apart a distance 110 and that extend into silicon substrate 102 , as illustrated in FIG. 5 .
- the trenches can be etched using any suitable etch chemistry conventionally used to form shallow trench isolation (STI).
- the photoresist layer is removed after completing the etching of trenches 106 .
- the patterned photoresist layer can be removed after being used as an etch mask for the etching of silicon nitride 104 .
- the etched layer of silicon nitride then can be used as a hard mask to mask the etching of silicon substrate 102 .
- the trenches 106 are filled with deposited oxide or other insulator, for example, by LPCVD or PECVD, to form members or spacers 108 .
- the deposited insulator fills trenches 106 , but is also deposited onto silicon nitride layer 104 .
- the excess insulator on silicon nitride layer 104 is polished back using chemical mechanical polishing (CMP) to complete the formation of STI, as illustrated in FIGS. 3-5 .
- CMP chemical mechanical polishing
- the silicon nitride then is removed, exposing silicon substrate 102 and leaving spacers 108 extending above the surface of substrate 102 .
- semiconductor devices 112 are formed on the exposed silicon substrate 102 between the spacers 108 .
- Semiconductor devices 112 may be flash EEPROM memory cells, such as flash EEPROM memory cells 10 of FIGS. 1 and 2 , that comprise a vertical gate stack 80 , a drain region 118 , and a source region 122 or may be other suitable semiconductor devices, such as field effect transistors (FETs), logic devices, other memory devices, and the like.
- FETs field effect transistors
- two adjacent vertical gate stacks 80 such as a first gate stack 114 and a second gate stack 116 , may be formed so that they share a first common impurity doped region, such as drain region 118 having a conductive contact (not shown), that is formed in silicon substrate 102 and to which contact is desired.
- First impurity doped region 118 may be formed in silicon substrate 102 in self-alignment with first and second gate stacks 114 and 116 or in any other conventional manner. Accordingly, first impurity doped region 118 is bounded by first and second gate stacks 114 , 116 and two spacers 108 .
- first semiconductor device 114 also may share a second common impurity doped region, such as source region 122 , having a conductive contact (not shown), with an adjacent third semiconductor device 120 . If contact will not be made to second common impurity doped region 122 , a distance 126 between first semiconductor device 114 and third semiconductor device 120 can be minimized to increase and/or maximize device density.
- an etch stop layer 119 may be deposited overlying semiconductor structure 100 .
- etch stop layer 119 comprises a nitride layer, although etch stop layer may comprise any suitable etch stop material, and has a thickness of about 30 to about 50 nm.
- etch stop layer 119 may be used to protect first common impurity doped region 118 from subsequent etching processes.
- a dielectric layer 128 is globally deposited overlying semiconductor structure 100 , as illustrated in FIGS. 13-16 .
- Dielectric layer 128 may comprise any suitable insulating material that can be deposited conformally.
- dielectric layer 128 may be an oxide material, formed from a material such as tetraethyl orthosilicate (TEOS), silicon dioxide, and the like.
- TEOS tetraethyl orthosilicate
- dielectric layer 128 is formed from TEOS.
- Dielectric layer 128 may be deposited by any suitable, well-known method such as LPCVD, PECVD, and the like. Dielectric layer 128 is sufficiently thin so that it conforms to the topography of semiconductor structure 100 .
- dielectric layer 128 is deposited to a sufficient thickness indicated by double headed arrow 129 so that, upon formation of a contact to the first common impurity doped region 118 , gate stacks 114 and 116 are sufficiently insulated from a subsequently formed unrelated conductive line that the conductive line does not interfere with or otherwise negatively affect the operation of the semiconductor devices.
- a plurality of depressions 130 of dielectric layer 128 forms between the various semiconductor devices 112 and the spacers 108 .
- a deep depression 132 of the plurality of depressions 130 forms between first gate stack 114 and second gate stack 116 and overlies first common impurity doped region 118 .
- the dimensions of depression 132 are dependant upon the distance 110 between adjacent spacers 108 , the distance 124 between gate stacks 114 and 116 , a height 136 of spacers 108 as measured from silicon substrate 102 , and the thickness 129 of dielectric layer 128 .
- distance 110 may be in the range of about 100 nm to about 200 nm
- distance 124 may be in the range of about 100 nm to about 200 nm
- height 136 may be in the range of about 200 nm to about 400 nm
- the thickness of dielectric layer 128 may be in the range of about 400 nm to about 800 nm.
- a layer of fill material 138 is globally deposited overlying semiconductor structure 100 , substantially filling depressions 130 .
- FIGS. 17-19 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 14-16 , respectively.
- Fill material 138 may comprise any suitable material that has an etch rate that is slower than the etch rate of dielectric layer 128 when subjected to the same etch chemistry.
- fill material 138 may comprise a silicon nitride deposited by PECVD, LPCVD, or any other suitable method.
- fill material 138 may comprise tungsten/titanium nitride (W/TiN), that is, a TiN barrier layer, preferably with a thickness of about 10 nm to about 30 nm, with a W core.
- W/TiN tungsten/titanium nitride
- the W/TiN may be deposited by CVD, PECVD, or the like. It will be appreciated, however, that the invention is not limited to silicon nitride or W/TiN and that any suitable fill material may be used.
- Any excess fill material 138 deposited outside depressions 130 and overlying dielectric layer 128 may be removed, such as by etching or, preferably, CMP to expose a surface 140 of dielectric layer 128 .
- the CMP is continued for a time such that the shallow depressions 130 that do not overlie first common impurity doped region 118 , and the fill material 138 therein, are removed, while deep depressions 132 , and the fill material 138 therein, remain.
- dielectric layer 128 may be subjected to CMP to remove shallow depressions 130 that do not overlie first common impurity doped region 118 , while leaving at least a portion of deep depressions 132 in tact. Fill material 138 then may be deposited to fill deep depressions 132 . Any excess fill material deposited outside deep depressions 132 and overlying dielectric layer 128 may be removed, such as by etching or, preferably, CMP to expose surface 140 of dielectric layer 128 .
- fill material 138 and dielectric layer 128 then are etched such that dielectric layer 128 is etched at a faster rate than fill material 138 .
- FIGS. 20 and 21 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 17 and 19 , respectively. If dielectric layer 128 is a silicon oxide and fill material 138 is silicon nitride, the dielectric layer and the fill material can be etched, for example, by plasma etching using a C 4 F 8 chemistry. A portion of dielectric layer 128 is removed by the etching process, resulting in at least a portion of fill material 138 extending from depressions 132 beyond surface 140 of dielectric layer 128 .
- a thickness of about 30 nm to 200 nm is removed from surface 140 of dielectric layer 128 .
- a thickness of dielectric layer 128 remains overlying gate stacks 80 of semiconductor devices 112 to insulate semiconductor devices 112 from a subsequently formed conductive line.
- a masking layer 142 is deposited overlying semiconductor structure 100 .
- FIGS. 22-24 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 17-19 , respectively.
- Masking layer 142 may comprise any material that etches at a slower rate than the etch rates of dielectric layer 128 and fill material 138 when subjected to the same etch chemistry.
- Masking layer 142 may comprise amorphous silicon, polysilicon, or any other suitable masking material.
- the masking layer may be deposited by any suitable known method and preferably is deposited to a thickness of about 60 nm to about 120 nm.
- FIGS. 25 and 26 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 22 and 24 , respectively.
- Masking layer 142 thus is self aligned to fill material 138 .
- FIGS. 27-29 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 22-24 , respectively.
- the etching chemistry may be any known etching chemistry that is selective to masking layer 142 .
- an etch stop layer such as etch stop layer 119 of FIG. 12 , overlies first common impurity doped region 118 to protect it from the etching chemistry.
- Masking layer 142 serves as a self aligned etch mask during the etching process and the etching process is continued until first common impurity doped region 118 , a conductive contact (not shown) electrically coupled thereto, or etch stop layer 119 is exposed. As noted above, masking layer 142 is self aligned to fill material 138 . The dimensions of fill material 138 are dependant upon the dimensions of depression 132 , which in turn are dependant upon the distance 110 between adjacent spacers 108 , the distance 124 between gate stacks 114 and 116 , height 136 of spacers 108 , and the thickness 129 of dielectric layer 128 , as illustrated in FIGS. 13-16 .
- via 144 dimensions of via 144 , such as a width indicated by double headed arrow 156 , a depth indicated by double headed arrow 152 , and a length indicated by double headed arrow 154 , are dependant on the same factors as depression 132 .
- a layer of spacer material 150 may be conformally deposited with a thickness of about 5 to 100 nm overlying dielectric material 128 and about the extended portions of fill material 138 and any residual dielectric material 128 remaining about the extended portions of fill material 138 .
- FIGS. 33 and 34 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 20 and 21 , respectively. Spacer material 150 may be used to increase the width of a subsequently formed contact.
- Spacer material 150 may be formed of any suitable material that etches at a faster rate than the etch rate of masking layer 142 when subjected to the same etch chemistry.
- spacer material 150 may be formed of a nitride, an oxide, an oxynitride, or the like, by PECVD, LPCVD, or the like.
- Masking layer 142 then may be deposited overlying spacer material 150 to a suitable thickness.
- FIGS. 35 and 36 illustrate semiconductor structure 100 along the same cross-sectional axes as FIGS. 33 and 34 , respectively.
- a sidewall spacer 158 of spacer material 150 is formed about the extended portion of fill material 138 and any of dielectric layer 128 about the extended portion of fill material 138 .
- Fill material 138 within depressions 132 , sidewall spacers 158 , and dielectric layer 128 then are etched until via 144 is formed.
- the process may continue as described above with reference to FIGS. 27-32 . Accordingly, because mask layer 142 is self-aligned with sidewall spacers 158 , the width 156 and length 154 of via 144 may be increased beyond the corresponding dimensions of fill material 138 upon etching of fill material 138 , residual dielectric layer 128 , and spacer material 150 .
- the spacer material 150 may be deposited to a thickness that covers fill material 138 .
- the spacer material 150 then may be etched using any suitable etch chemistry that is selective to dielectric layer 128 , such as CH 3 F/O 2 , to form sidewall spacers 160 .
- Masking layer 142 then may be deposited to a suitable thickness, as described above.
- masking layer 142 Following the deposition of masking layer 142 , a portion of masking layer 142 is removed, preferably by CMP, to expose fill material 138 and sidewall spacers 160 while remaining overlying spacers 108 . Fill material 138 within depressions 132 , sidewall spacers 160 , and dielectric layer 128 are etched until via 144 is formed. The process then may continue as described above with reference to FIGS. 27-32 . Accordingly, because mask layer 142 is self-aligned with sidewall spacers 160 , the width 156 and length 154 of via 144 may be increased beyond the corresponding dimensions of fill material 138 upon etching of fill material 138 , residual dielectric layer 128 , and sidewall spacers 158 .
- one or more conductive materials may be deposited within via 144 to form a conductive contact 146 that is electrically coupled to first impurity doped region 118 .
- a metal such as tungsten (W), aluminum (Al), copper (Cu), gold (Au), silver (Ag), or the like, or alloys thereof, may be deposited within via 144 .
- the conductive contact 146 may be fabricated by depositing a barrier layer, a seed layer, and a conductive core material, as is well known.
- the barrier layer may be formed of tantalum (Ta), tantalum nitride (TaN), tantalum silicon nitride (TaSiN), cobalt (Co), titanium nitride (TiN), ruthenium (Ru), rhodium (Rh), palladium (Pd), or any other suitable metal that hinders or prevents the ability of the conductive core material from diffusing into or otherwise adversely reacting with surrounding materials.
- the barrier layer may be deposited using physical vapor deposition (PVD), ionized metal plasma (IMP), chemical vapor deposition (CVD), or any other suitable technique known in the semiconductor industry.
- the seed layer may be deposited using PVD, IMP, CVD or any other suitable technique known in the semiconductor industry.
- the conductive core may be formed by electroplating deposition, PVD, IMP, CVD, or any other suitable method.
- the seed layer and the conductive core may be comprised of tungsten (W), copper (Cu), aluminum (Al), gold (Au), silver (Ag), and the like, or any combined alloy thereof.
- any excess metal may be removed from the surface 140 of dielectric layer 128 such as by CMP or the like.
- masking layer 142 may be removed after the removal of the excess metal overlying surface 140 .
- an etch stop layer such as etch stop layer 119 of FIG. 12 , is present to protect first common impurity doped region 118 , masking layer 142 may be removed before deposition of the materials forming conductive contact 146 . The etch stop layer then may be removed
- a conductive interconnect 148 then may be formed overlying surface 140 of dielectric layer 128 to electrically couple semiconductor devices 112 to other devices, lines, or other features of the integrated circuit via conductive contact 146 . As illustrated in FIGS. 30 and 32 , semiconductor devices 112 are insulated from conductive interconnect 148 by dielectric layer 128 .
- a method for fabricating a semiconductor structure that provides a self-aligned contact to a semiconductor device reduces the masking and photolithography steps required to form the contact and eliminates misalignment problems associated with lithography of small contacts.
- the dimensions and locations of the contacts may be manipulated by manipulating the distance between adjacent semiconductor devices, the distance between adjacent spacers, and the height of the spacers.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
Abstract
Description
Claims (11)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/355,474 US7470614B1 (en) | 2006-02-15 | 2006-02-15 | Methods for fabricating semiconductor devices and contacts to semiconductor devices |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/355,474 US7470614B1 (en) | 2006-02-15 | 2006-02-15 | Methods for fabricating semiconductor devices and contacts to semiconductor devices |
Publications (1)
Publication Number | Publication Date |
---|---|
US7470614B1 true US7470614B1 (en) | 2008-12-30 |
Family
ID=40138478
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/355,474 Active 2026-08-22 US7470614B1 (en) | 2006-02-15 | 2006-02-15 | Methods for fabricating semiconductor devices and contacts to semiconductor devices |
Country Status (1)
Country | Link |
---|---|
US (1) | US7470614B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090117736A1 (en) * | 2007-11-01 | 2009-05-07 | Applied Materials, Inc. | Ammonia-based plasma treatment for metal fill in narrow features |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5710073A (en) * | 1996-01-16 | 1998-01-20 | Vanguard International Semiconductor Corporation | Method for forming interconnections and conductors for high density integrated circuits |
US20020098652A1 (en) * | 1998-06-08 | 2002-07-25 | Kabushiki Kaisha Toshiba | Semiconductor device having MISFETs |
US20040140510A1 (en) * | 2002-11-06 | 2004-07-22 | Kabushiki Kaisha Toshiba | Semiconductor memory device having a gate insulation film and a manufacturing method thereof |
US20050023600A1 (en) * | 2000-01-17 | 2005-02-03 | Samsung Electronics, Co. Ltd | NAND-type flash memory devices and methods of fabricating the same |
US20060017111A1 (en) * | 2004-07-23 | 2006-01-26 | Kabushiki Kaisha Toshiba | Semiconductor device and method of fabricating the same |
US20060223332A1 (en) * | 2005-03-30 | 2006-10-05 | Hynix Semiconductor Inc. | Method of manufacturing semiconductor device |
-
2006
- 2006-02-15 US US11/355,474 patent/US7470614B1/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5710073A (en) * | 1996-01-16 | 1998-01-20 | Vanguard International Semiconductor Corporation | Method for forming interconnections and conductors for high density integrated circuits |
US20020098652A1 (en) * | 1998-06-08 | 2002-07-25 | Kabushiki Kaisha Toshiba | Semiconductor device having MISFETs |
US20050023600A1 (en) * | 2000-01-17 | 2005-02-03 | Samsung Electronics, Co. Ltd | NAND-type flash memory devices and methods of fabricating the same |
US20040140510A1 (en) * | 2002-11-06 | 2004-07-22 | Kabushiki Kaisha Toshiba | Semiconductor memory device having a gate insulation film and a manufacturing method thereof |
US20060017111A1 (en) * | 2004-07-23 | 2006-01-26 | Kabushiki Kaisha Toshiba | Semiconductor device and method of fabricating the same |
US20060223332A1 (en) * | 2005-03-30 | 2006-10-05 | Hynix Semiconductor Inc. | Method of manufacturing semiconductor device |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090117736A1 (en) * | 2007-11-01 | 2009-05-07 | Applied Materials, Inc. | Ammonia-based plasma treatment for metal fill in narrow features |
US8551880B2 (en) * | 2007-11-01 | 2013-10-08 | Applied Materials, Inc. | Ammonia-based plasma treatment for metal fill in narrow features |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6861698B2 (en) | Array of floating gate memory cells having strap regions and a peripheral logic device region | |
US7776692B2 (en) | Semiconductor device having a vertical channel and method of manufacturing same | |
US7615807B2 (en) | Field-effect transistor structures with gate electrodes with a metal layer | |
EP1494276A2 (en) | Semiconductor device including nonvolatile memory and method for fabricating the same | |
US7521318B2 (en) | Semiconductor device and method of manufacturing the same | |
US7768061B2 (en) | Self aligned 1 bit local SONOS memory cell | |
JP2000357784A (en) | Nonvolatile semiconductor memory and manufacture thereof | |
KR101602251B1 (en) | Wiring structure and method for the forming the same | |
US7888804B2 (en) | Method for forming self-aligned contacts and local interconnects simultaneously | |
US7115491B2 (en) | Method for forming self-aligned contact in semiconductor device | |
US8460997B2 (en) | Semiconductor memory device and method of manufacturing the same | |
US20070059888A1 (en) | Semiconductor integrated circuit device and manufacturing method thereof | |
US6136649A (en) | Method for removing anti-reflective coating layer using plasma etch process after contact CMP | |
TWI582841B (en) | Method for fabricating transistor gate and semiconductor device comprising transistor gate | |
US6037247A (en) | Method of manufacturing semiconductor device having a self aligned contact | |
US7705390B2 (en) | Dual bit flash memory devices and methods for fabricating the same | |
US6486506B1 (en) | Flash memory with less susceptibility to charge gain and charge loss | |
US6429069B1 (en) | SOI DRAM with buried capacitor under the digit lines utilizing a self aligning penetrating storage node contact formation | |
US8012826B2 (en) | Semiconductor device and manufacturing method of same | |
US8823107B2 (en) | Method for protecting the gate of a transistor and corresponding integrated circuit | |
US6492227B1 (en) | Method for fabricating flash memory device using dual damascene process | |
US6878622B1 (en) | Method for forming SAC using a dielectric as a BARC and FICD enlarger | |
US20080146014A1 (en) | Self aligned contact | |
US7115471B2 (en) | Method of manufacturing semiconductor device including nonvolatile memory | |
US7470614B1 (en) | Methods for fabricating semiconductor devices and contacts to semiconductor devices |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SPANSION LLC, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WISEMAN, JOSEPH WILLIAM;REEL/FRAME:017589/0620 Effective date: 20051123 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: BARCLAYS BANK PLC,NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:SPANSION LLC;SPANSION INC.;SPANSION TECHNOLOGY INC.;AND OTHERS;REEL/FRAME:024522/0338 Effective date: 20100510 Owner name: BARCLAYS BANK PLC, NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:SPANSION LLC;SPANSION INC.;SPANSION TECHNOLOGY INC.;AND OTHERS;REEL/FRAME:024522/0338 Effective date: 20100510 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: SPANSION LLC, CALIFORNIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:BARCLAYS BANK PLC;REEL/FRAME:035201/0159 Effective date: 20150312 Owner name: SPANSION INC., CALIFORNIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:BARCLAYS BANK PLC;REEL/FRAME:035201/0159 Effective date: 20150312 Owner name: SPANSION TECHNOLOGY LLC, CALIFORNIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:BARCLAYS BANK PLC;REEL/FRAME:035201/0159 Effective date: 20150312 |
|
AS | Assignment |
Owner name: MORGAN STANLEY SENIOR FUNDING, INC., NEW YORK Free format text: SECURITY INTEREST;ASSIGNORS:CYPRESS SEMICONDUCTOR CORPORATION;SPANSION LLC;REEL/FRAME:035240/0429 Effective date: 20150312 |
|
AS | Assignment |
Owner name: CYPRESS SEMICONDUCTOR CORPORATION, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SPANSION, LLC;REEL/FRAME:036044/0745 Effective date: 20150601 |
|
AS | Assignment |
Owner name: SPANSION LLC, CALIFORNIA Free format text: PARTIAL RELEASE OF SECURITY INTEREST IN PATENTS;ASSIGNOR:MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT;REEL/FRAME:039708/0001 Effective date: 20160811 Owner name: CYPRESS SEMICONDUCTOR CORPORATION, CALIFORNIA Free format text: PARTIAL RELEASE OF SECURITY INTEREST IN PATENTS;ASSIGNOR:MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT;REEL/FRAME:039708/0001 Effective date: 20160811 |
|
REMI | Maintenance fee reminder mailed | ||
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
SULP | Surcharge for late payment |
Year of fee payment: 7 |
|
AS | Assignment |
Owner name: MONTEREY RESEARCH, LLC, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CYPRESS SEMICONDUCTOR CORPORATION;REEL/FRAME:040911/0238 Effective date: 20160811 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 12 |
|
AS | Assignment |
Owner name: MORGAN STANLEY SENIOR FUNDING, INC., NEW YORK Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE 8647899 PREVIOUSLY RECORDED ON REEL 035240 FRAME 0429. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY INTERST;ASSIGNORS:CYPRESS SEMICONDUCTOR CORPORATION;SPANSION LLC;REEL/FRAME:058002/0470 Effective date: 20150312 |